The Democratic Senatorial Campaign Committee, or DSCC, ordered $1 million in ads to run for the next two weeks, the group’s first advertising to help first-term Sen. Mark Udall and his close re-election bid. Millions of dollars already had been spent in Colorado, and millions more were expected to come in the final push toward Election Day.

In the 30-second ads, Democrats warn that Gardner sought to change Colorado’s constitution to roll back abortion rights and outlaw the procedure in the cases of rape and incest. Gardner, a second-term congressman, also has co-sponsored an anti-abortion bill in Congress, the ad concludes.

“Why do guys like Cory Gardner think it’s any of their business to tell women what do?” a young female voter asks into the camera.

Adds an older woman: “Cory Gardner is way too extreme for Colorado.”

Gardner supported changes to Colorado’s state constitution that would have given fertilized eggs the same rights as a person. Voters twice rejected the proposal, which would have banned stem cell research, some birth control and abortion.

Gardner has since changed his position on the state’s so-called personhood measure and says now he opposes it.

The ad also criticizes Gardner for backing a U.S. House bill that would ban abortions for victims of rape or incest. Democrats point to the Life at Conception Act, which has been introduced but has not yet been considered.

Gardner’s campaign countered with a bill Gardner is co-sponsoring that, in addition to denying federal funds to any health provider that offers abortions, carves out exemptions if the woman’s life is at risk or the pregnancy were the result of rape or incest. That bill, too, has not been considered by the House.

The DSCC ads come just days after Crossroads GPS, backed by GOP strategist Karl Rove, ordered $6 million in ads for Colorado. Those ads are slated to start Sept. 23.

Spending on the race already has topped $18 million, according to data compiled by the nonpartisan Sunlight Foundation.

The high level of spending shows just how competitive Colorado is shaping up to be. Republicans are gunning to pick up six Senate seats and, with them, control of the chamber for the first time since after the 2006 midterm elections.